\documentclass{minimal}
\begin{document}

\begin{blacklist}
  Not folded

  \begin{itemize}
    \item Not folded
  \end{itemize}

  \begin{whitelist}
    Folded.
  \end{whitelist}

  \begin{both}
    Not folded
  \end{both}
\end{blacklist}

\end{document}
